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The effects of ultraviolet radiation on growth and bleaching in three species of Hawaiian coral

Conference · · EOS, Transactions, American Geophysical Union; (United States)
OSTI ID:6617070
 [1]
  1. California State Univ., Long Beach (United States)

Long term exposure to ultraviolet radiation is harmful to many organisms, including hermatypic corals, which obtain much of their nutrition from photosynthetic zooxanthellae. Therefore, increased UV radiation from atmospheric ozone depletion could inhibit growth of such corals. Moreover, coral bleaching, which has been attributed to loss of pigment and/or expulsion of zooxanthellae, may be a specific response to UV light. Does UV-A reduce skeletal growth or influence population density and pigment content of zooxanthellae In addition, do zooxanthellae migrate to shaded areas of the colony to avoid ultraviolet light Using alizarin red stain and suitable filters, I compared the stain and suitable filters, I compared the effects of UV-A (320-400nm) and full-spectrum UV (280-400nm) on the skeletal growth of two Hawaiian corals, Montipora verrucosa, Pocillopora damicornis, in situ. In the perforate corals, M. Verrucosa and Porites compressa, I measured concentration of zooxanthellae and their chlorophyll content to quantify bleaching in response to UV light. Reduction in skeletal growth by the two corals in response to different ranges of UV light appears to be species specific. Bleaching by UV appears to be characterized by an initial loss of pigment followed by the expulsion and migration of the zooxanthellae to shaded areas of the colony. Differences in tolerance and adaptation to decreasing ozone levels and increasing UV light should confer a competitive advantage on various species and morphologies of reef-building corals.

OSTI ID:
6617070
Report Number(s):
CONF-9002174--
Journal Information:
EOS, Transactions, American Geophysical Union; (United States), Journal Name: EOS, Transactions, American Geophysical Union; (United States) Vol. 71:2; ISSN 0096-3941; ISSN EOSTAJ
Country of Publication:
United States
Language:
English